1. Field of the Invention
The present invention relates generally to vibration dampening devices and more particularly to vibration dampening devices for hand held sporting rackets having a strung striking surface, such as tennis rackets.
2. Background of the Invention
Most strung hand held sporting rackets have a striking surface or face formed of two intersecting sets of parallel strings suspended by and enclosed by an oval frame. One set of strings extends generally parallel to the handle of the racket and may be called the longitudinal strings, while the other set of strings extends generally transversely of the handle and may be called the transverse strings. In such rackets, vibrations are produced in the racket face when a ball is struck. The vibrations are most severe when the ball does not strike the racket face in the center thereof, but strikes it at a distance spaced from the center. Initially, rather large vibration is detected in the racket face and this initial vibration is followed by a series of smaller vibrations which eventually die out with time. Such vibrations are transmitted generally along the transverse and longitudinal strings of the racket, to the frame surrounding and holding the strings, and eventually down the racket handle to the hand and then the arm of the player. It has been shown that a player who has been subject to extensive periods of racket-induced vibrations can sustain "tennis elbow" injury to his or her arm. It is therefore desirable to reduce such vibrations both for the comfort and protection of the player.
Devices for dampening the vibrations in a tennis racket are well known. A typical device is shown in U.S. Pat. Nos. 4,180,265; 4,609,194 and 4,776,590. Such dampeners couple together and interlock racquet strings. Devices as shown in prior patents have not been entirely successful, since they are sometimes difficult to attach to the racket face, and can interfere with the flight of the ball if struck by the ball. Also, such devices often fall off the racket strings during play.
Other devices which interconnect the strings of a racket include U.S. Pat. Nos.: 4,368,886; 3,921,979; 4,078,796; 4,168,065; and 1,682,199; and International Patent Institute 81/03431 which discloses a pair of pads secured together on the strings by screws, bolts or the like.